Organotin compounds, particularly useful as stabilizers, for halogen containing polymers, are well known in the art. These organotin compounds can provide stabilization of such polymers when used alone or in combination with various compounds. For example, U.S. Pat. No. 3,715,333 to W. A. Larkin discloses stabilizers for halogen containing polymers which contain, as a first stabilizer, an organotin halide having the formula: EQU RSnX.sub.3
where R is a hydrocarbon and X is chlorine, bromine, or iodine; and, as a second stabilizer, a sulfur-containing organotin compound exhibiting two direct carbon to tin bonds and a direct bond from tin to each of two sulfur atoms. Likewise, U.S. Pat. No. 3,503,924 to M. W. Pollock discloses stabilizers for polyvinyl chloride resins which are mixtures containing a diorganotin mercaptide and a minor amount of an alpha-mercapto acid. Pollock also discloses, in U.S. Pat. No. 3,507,827, stabilizer combinations for decreasing early discoloration of polyvinyl chloride resins which contain (1) a dialkyl, dicycloalkyl or alkylcycloalkyl tin mercapto carboxylic acid ester, and (2) an alpha- or beta-mercapto acid having at least three carbon atoms, or an alpha- or beta-mercapto alcohol having at least two carbon atoms.